You go to a doc. They’ll usually give you a form to fill out and it’s really a self evaluation. Answer enough questions the “right way” and they’ll take a closer look.
For me, the confirmation of the condition was after taking the new rx for a few days. “Oh, THIS is what a quiet mind is!”
Holy shit that makes my blood boil! If I earned a B you fucking give me a B, marks are not arbitrary and based on your feelings.
We had a teacher like this for my youngest son. Her marking of his work was consistently two letter grades below every other mark he got in all of his subjects. Got the school board involved after having a few other teachers independently grade the same paper she gave him a C on. She is no longer involved in any of his studies.